similar to: best selection of covariates (for each individual)

Displaying 20 results from an estimated 10000 matches similar to: "best selection of covariates (for each individual)"

2010 Aug 11
4
Arbitrary number of covariates in a formula
Hello! I have something like this: test1 <- data.frame(intx=c(4,3,1,1,2,2,3), status=c(1,1,1,0,1,1,0), x1=c(0,2,1,1,1,0,0), x2=c(1,1,0,0,2,2,0), sex=c(0,0,0,0,1,1,1)) and I can easily fit a cox model: library(survival) coxph(Surv(intx,status) ~ x1 + x2 + strata(sex),test1) However, I want to
2008 Dec 28
1
Random coefficients model with a covariate: coxme function
Dear R users: I'm new to R and am trying to fit a mixed model Cox regression model with coxme function. I have one two-level factor (treat) and one covariate (covar) and 32 different groups (centers). I'd like to fit a random coefficients model, with treat and covar as fixed factors and a random intercept, random treat effect and random covar slope per center. I haver a couple of
2002 Feb 20
3
Pointer to covariates?
In the first line, use the dist function, found in library mva, to get the distance between each pair of rows. From this calculate an incidence matrix for which element i,j is true if row i in dat equals row j in dat (and false elsewhere). In the second line, for each row calculate the indices of the matching rows and take the minimum of those as the key. incid <-
2012 Oct 04
1
geoRglm with factor variable as covariable
Dear R users. I'm trying to fit a generalised linear spatial mode using the geoRglm package. To do so, I'm preparing my data (geodata) as follow: geoData9093 = as.geodata(data9093, coords.col= 17:18, data.col=15,* covar.col=16*) where covar.col is a factor variable (years in this case 90-91-92-93)). Then I run the model as follow: / model.5 = list(cov.pars=c(1,1),
2008 Feb 20
3
reshaping data frame
Dear all, I'm having a few problems trying to reshape a data frame. I tried with reshape{stats} and melt{reshape} but I was missing something. Any help is very welcome. Please find details below: ################################# # data in its original shape: indiv <- rep(c("A","B"),c(10,10)) level.1 <- rpois(20, lambda=3) covar.1 <- rlnorm(20, 3, 1) level.2
2010 Jun 02
2
glmnet strange error message
Hello fellow R users, I have been getting a strange error message when using the cv.glmnet function in the glmnet package. I am attempting to fit a multinomial regression using the lasso. covars is a matrix with 80 rows and roughly 4000 columns, all the covariates are binary. resp is an eight level factor. I can fit the model with no errors but when I try to cross-validate after about 30 seconds
2017 Oct 06
1
How to resolve this error
> library(SpatioTemporal) > library(plotrix) > library(maps) > palay.cov<-read.csv("C:/Users/BEDANA-PC/Desktop/STThesisWD/Thesis Data/palay.covar.csv") > palay.o<-read.table("C:/Users/BEDANA-PC/Desktop/STThesisWD/Thesis Data/palay.obs.txt") > palay.obs<-as.matrix(palay.o) > palay.stc<-read.table("C:/Users/BEDANA-PC/Desktop/STThesisWD/Thesis
2008 Jan 15
1
covariate in a glm
Hello mailing list! I would like to know, how I can introduce a covariate in a glm, I've two factors and a covariate. Thank you very much! _______________________________________________________________________________________________ Michelangelo La Spina Equipo de Protección de cultivos - Control Biológico Departamento de Biotecnología y Protección de Cultivos Instituto Murciano de
2005 Jun 24
1
interpreting Weibull survival regression
Hi, I was wondering if someone can help me interpret the results of running weibreg. I run the following and get the following R output. > weibreg(Surv(time, censor)~covar) fit$fail = 0 Call: weibreg(formula = Surv(time, censor)~covar) Covariate Mean Coef Rel.Risk L-R p Wald p covar 319.880 -0.002 0.998 0.000 log(scale) 0.000 8.239
2013 Mar 11
2
How to 'extend' a data.frame based on given variable combinations ?
Dear expeRts, I have a data.frame with certain covariate combinations ('group' and 'year') and corresponding values: set.seed(1) x <- data.frame(group = c(rep("A", 4), rep("B", 3)), year = c(2001, 2003, 2004, 2005, 2003, 2004, 2005), value = rexp(7)) My goal is essentially to
2018 Feb 09
0
Covariates in fuzzy RDD with rddtools
Hello! I am having trouble including covariates in a fuzzy RDD model in R with rddtools. I run the following commands: library(rddtools) data.complete2 <- as.data.frame(cbind(GDPpc.rel, GR.rate, fitval.firstStage)) colnames(data.complete2) <- c("GDPpc.rel", "GR.rate", "FitTreat") data.RDD<-rdd_data(x=data.complete2$GDPpc.rel,
2008 Aug 18
1
GeoR model.control - defining covariates at prediction locations
Hi, Im using geoR and I'm trying to do some predictions, based on an external trend. I'm having some problems specifying my model.control, specifically how do I define my model, and also the source of the covariate data at the prediction locations? I am assuming that the covariate data at the prediction locations should be imported to a geodata object along with the prediction location
2010 Jan 28
1
AFT-model with time-varying covariates and left-truncation
Dear Prof. Brostr?m, Dear R-mailinglist, first of all thanks a lot for your great effort to incorporate time-varying covariates into aftreg. It works like a charm so far and I'll update you with detailled benchmarks as soon as I have them. I have one more questions regarding Accelerated Failure Time models (with aftreg): You mention that left truncation in combination with time-varying
2006 Sep 14
1
time varying covariates
Hello, I am trying to model an intensity function with time-varying covariates. Before, I have successfully defined a log likelihood function for a Power-Law Process (lambda(t)=alpha*beta*t^(beta-1)) with two paramters and no covariates for a repairable systems with failure times (t). This function was maximized with R optim. No problem! But now I want to include a covariate indicating a
2009 Apr 29
1
meta regression in R using lme function
Dear all, We are trying to do a meta regression in R using the lme function. The reason for doing this with lme function is that we have covariates and studies within references. In S-Plus this is possible by using the following command: lme(outcome ~ covars, random = ~1 | reference/study, weights = varFixed(~var.outcome), data = mydata, control = lmeControl(sigma = 1)) This means that the
2010 Jan 07
1
faster GLS code
Dear helpers, I wrote a code which estimates a multi-equation model with generalized least squares (GLS). I can use GLS because I know the covariance matrix of the residuals a priori. However, it is a bit slow and I wonder if anybody would be able to point out a way to make it faster (it is part of a bigger code and needs to run several times). Any suggestion would be greatly appreciated. Carlo
2004 Aug 19
7
A question about external time-dependent covariates in co x model
Dear Rui, >From my understanding of time-dependent covariates (not an expert but have been working on a similar problem), it would appear that the coding of the status column is not correct. Unless you have observed an event at each interval you should only have status=1 for the last interval. In your example I see 3 in total. Also, I think that if "end" is proportional to your
2006 Feb 22
1
var-covar matrices comparison
> Date: Mon, 20 Feb 2006 16:43:55 -0600 > From: Aldi Kraja <aldi at wustl.edu> > > Hi, > Using package gclus in R, I have created some graphs that show the > trends within subgroups of data and correlations among 9 variables (v1-v9). > Being interested for more details on these data I have produced also the > var-covar matrices. > Question: From a pair of two
2004 Aug 13
1
How to use the whole dataset (including between events) in Cox model (time-varying covariates) ?
Hello, coxph does not use any information that are in the dataset between event times (or "death times") , since computation only occurs at event times. For instance, removing observations when there is no event at that time in the whole dataset does not change the results: > set.seed(1) > data <- as.data.frame(cbind(start=c(1:5,1:5,1:4),stop=c(2:6,2:6,2:5),status=c(rep(
2009 Feb 27
2
Competing risks adjusted for covariates
Dear R-users Has anybody implemented a function/package that will compute an individual's risk of an event in the presence of competing risks, adjusted for the individual's covariates? The only thing that seems to come close is the cuminc function from cmprsk package, but I would like to adjust for more than one covariate (it allows you to stratify by a single grouping vector). Any